5.
Sam and Rory had gotten along swimmingly since day one. Rory liked Sam because Sam never ignored him or laughed at him like the Doctor and Dean and Amy. Every time Amy wanted to surprise him with something (which she liked to do quite frequently now that she’d realized his proneness for death), the Doctor would dance around the TARDIS console, rambling on about some amazing place. Then he would park it, turn around, look straight at Rory and announce “Rory, you stay here.”
Rory, you stay here. It made him feel like a dog. Like a little Labrador puppy they were trying to housebreak. But it was okay now that Sam was around. Sam would always stick around when everyone ditched Rory. Their favorite thing to do when they had the TARDIS all to themselves was to play the Doctor’s old Playstation One. The Doctor had every single game ever created for the console.
And Sam was quite good at Playstation.